Abstract
Intramolecular photodimerization of the photochromic molecule 9-hydroxymethyl-10-[(1-naphthyl methoxy)methyl]anthracene (HNMA) was investigated by ultraviolet-visible (UV-vis) spectroscopy in the glassy region of poly(methyl methacrylate) (PMMA) under different aging conditions. The PMMA matrix was annealed for different time intervals in the glassy region after quenching from 140°C (37.8°C above the glass transition temperature (Tg)). By following the photodimerization upon irradiation with linearly polarized light, it was found that the reaction kinetics of HNMA reflects the rearrangements of local free-volumes of the matrix. The maximum efficiency (ηmax) of the reaction induced by linearly polarized light decreases with increasing aging time (ta). Under aging above 60°C, ηmax decreased monotonously with aging time, whereas it did not change systematically for a PMMA aged at 40°C. The secondary relaxation of the PMMA matrix may thus play a key role in the aging process at low temperature. On the other hand, the reaction kinetics of HNMA can be well expressed by the sum of two exponential functions of irradiation time and a baseline. The two fractions of these decay processes are significantly affected by aging time whereas the influence on the two reaction rates is less remarkable. The baseline increases with increasing aging time, reflecting shrinkage of samples under aging. These experimental results are discussed in relation to the aging data obtained by other techniques such as dielectric relaxation and dynamic mechanical measurements.
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References
L. C. E. Struik, “Physical Aging in Amorphous Polymers and Other Materials,” Elsevier, Amsterdam, 1978.
L. Guerdoux, R. A. Duckett, and D. Froelich, Polymer, 25, 1392 (1984).
L. Guerdoux and E. Marchal, Polymer, 22, 1199 (1981).
S. R. Jong, J. S. Lee, and T.-L. Yu, Macromol. Chem. Phys., 198, 2373 (1997).
L. Lamarre and C. S. P Sung, Macromolecules, 16, 1729 (1983).
C. S. P. Sung, L. Lamarre, and K. H. Chung, Macromolecules, 14, 1839 (1981).
J. G. Victor and J. M. Torkelson, Macromolecules, 20, 2241 (1987).
I. Mita, K. Horie, and K. Hirao, Macromolecules, 22, 558 (1989).
C. Y. Stacey Fu, H. S. Lackritz, D. B. Priddy, Jr., and J. E. McGrath, Macromolecules, 29, 3470 (1996).
E. F. Meyer, A. M. Jamieson, and R. Simha, Polymer, 31, 243 (1990).
J. S. Royal and J. M. Torkelson, Macromolecules, 26, 5331 (1993).
H. Kanato, D. H. Hua, and Q. Tran-Cong, Macromolecules, 27, 7907 (1994).
Q. Tran-Cong, “Polarization-Selective Photochromic Reactions in Polymer Solids” in “Polymeric Materials Encyclopedia,” Vol. 7, CRC Press, Boca Raton, FL, 1966, p 5928.
A. Morita and Q. Tran-Cong, Physica A, 242, 377 (1997).
Q. Tran-Cong, T. Kumazawa, O. Yano, and T. Soen, Macromolecules, 23, 3002 (1990).
R. J. Cherry, Biochim. Biophys. Acta, 559, 289 (1979).
H. Yoshizawa, K. Ashikaga, M. Yamamoto, and Q. Tran-Cong, Polymer, 30, 534 (1989).
G. Williams and D. C. Watts, Trans. Faraday Soc., 66, 80 (1971).
G. B. McKenna and A. J. Kovacs, Polym. Eng. Sci., 24, 1138 (1984).
Q. Tran-Cong, S. Chikaki, and H. Kanato, Polym. Commun., 35, 4465 (1994).
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Yamaguchi, Y., Okamoto, T., Urakawa, O. et al. Effects of Physical Aging on Polarization-Induced Photodimerization in the Glassy Region of Poly(methyl methacrylate). Polym J 30, 414–420 (1998). https://doi.org/10.1295/polymj.30.414
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DOI: https://doi.org/10.1295/polymj.30.414